Jack Dykinga / Storm clouds at sunset over balancing eroded boulder, Texas Canyon, Little Dragoon Mountains, Chihuahuan Desert, Arizona, USA. September.

Yva Momatiuk & John Eastcott / Ripples on white gypsum sand dunes, White Sands National Park, New Mexico

Jouan Rius / Gypsum sand dune at sunset, White Sands National Park, Chihuahuan Desert, New Mexico, USA, December 2012.

Rolf Nussbaumer / Blue-throated Hummingbird (Lampornis clemenciae) male feeding on flowering Claret Cup Cactus (Echinocereus triglochidiatus) Chisos Basin, Chisos Mountains, Big Bend National Park, Chihuahuan Desert, W...

Patricio Robles Gil / Barrel cactus (Ferocactus pilosus) Chihuahuan desert, Mexico

Jack Dykinga / Close-up of two Barrel cacti (Ferocactus acanthodes) in the eastern Chihuahuan Desert, Mexico

Jack Dykinga / A cluster of flowering Barrel cacti (Ferocactus stainsii) with Yuccas (Yucca sp) in the Eastern extension of the Chihuahuan Desert, Tamaulipas, Mexico

Jack Dykinga / Flowering redbud (Cercis sp) in a heavily vegetated arroyo / valley in the Chihuahuan Desert, Tamaulipas, Mexico

Jack Dykinga / Flowering redbud (Cercis sp) amid agaves (Agave sp) on a north-facing hillside in the Chihuahuan Desert, Tamaulipas, Mexico

Jack Dykinga / Clusters of Barrel Cacti (Ferocactus stainesii) and Yuccas (Yucca sp) with the Sierra Madre in the background, Chihuahuan Desert, Mexico, Central America

Tim Fitzharris / Vervain (Verbena officinalis) at Franklin Mountains State Park, Chihuahuan Desert, Texas

Tim Fitzharris / Opuntia (Opuntia sp) in Chihuahuan Desert landscape, Big Bend National Park, Texas